Watanabe Ryuichi, Samusawa-Saito Ritsumi, Oshima Yasukatsu
Laboratory of Bioorganic Chemistry, Graduate School of Life Sciences, Tohoku University, Sendai 981-8555, Japan
Bioconjug Chem. 2006 Mar-Apr;17(2):459-65. doi: 10.1021/bc049699e.
Saxitoxin (STX) and its analogues accumulated in bivalves cause food poisoning through the blockade of sodium channels in the nervous system. In the current studies, STX-conjugated agarose gels as affinity chromatography reagents were prepared for investigation of the fate of the toxins in natural environments and in the human body. A carboxyl moiety was introduced through positions C11 and C13 to leave the most characteristic part of the molecule intact. Two types of synthesized derivatives, 11-(2-carboxyethylthio)saxitoxin and 13-O-hemisuccinyldecarbamoylsaxitoxin, were successfully conjugated to Sepharose 4B in high yield. Affinity gels containing 500 nmol of STX or decarbamoylsaxitoxin per milliliter of gel were accomplished by masking the residual amino groups by acetylation. Finally, the STX-conjugated affinity gel was effective for concentrating STX-binding proteins from pufferfish and bullfrog plasma.
双壳贝类中积累的石房蛤毒素（STX）及其类似物通过阻断神经系统中的钠通道导致食物中毒。在当前的研究中，制备了STX偶联的琼脂糖凝胶作为亲和色谱试剂，用于研究毒素在自然环境和人体中的命运。通过C11和C13位引入羧基部分，以使分子最具特征的部分保持完整。两种合成衍生物，即11-（2-羧乙基硫基）石房蛤毒素和13-O-半琥珀酰脱氨甲酰石房蛤毒素，成功地以高产率与琼脂糖4B偶联。通过乙酰化掩盖残留氨基，制成每毫升凝胶含有500 nmol STX或脱氨甲酰石房蛤毒素的亲和凝胶。最后，STX偶联的亲和凝胶可有效从河豚和牛蛙血浆中浓缩STX结合蛋白。
